1. Field of the Invention
The invention is related to a method to assemble a turn signal indicator that is installed into a rear view mirror. More especially the invention is also related to a light guide sub module that is mounted with a lens and inserted in an opening of the mirror head cover or between mirror cover elements.
2. Description of The Related Art
Solutions with turn signal indicators in the mirror head of an exterior rear view mirror are known since long. The first solutions comprised signal light bulbs placed at different positions of the rear view mirror. With the availability of LEDs as light sources for turn signal indication also devices with light guides are disclosed.
In the U.S. Pat. No. 7,255,464 a lot of different rear view mirror designs are disclosed using in some embodiments a light guide to emit light in forward direction of the vehicle.
In the embodiments of FIG. 98 and FIG. 99 of this prior art a design is shown with a light guide and additional LED sources positioned along the light guide.
In EP1391348 A2 a LED is mounted in a hole of a light guide. The small printed circuit board is also hosted in the mounting hole. The light guide does not have special protrusions to fix printed circuit board and light guide.
The need in automotive supply industry to reduce costs results in solutions with a single LED as light source for a turn signal indicator with a light guide. The LED is positioned at one end of the light guide. A solution using a LED and a light guide is shown in EP0858932. In this assembly and in common production processes the single LED is mounted on a printed circuit board that is fixed to the housing of the turn signal indicator module. To mount the printed circuit board in the housing has the advantage that the contact to electrical harness can be provided easily.
During assembly the light guide with the integrated lens is vibration-welded to the housing closing the module. The welding process works independent from the position of the LED and results in a deviation form optimum of LED to light guide end face allocation.
There is a need to improve the production process in an easy and cost saving way and to optimize the spatial relation between LED and light guide during production.
The light of a single LED or of a small amount of LEDs must be efficiently fed into the light guide. Any deviation results in a reduction of light power emitted through the light guide decoupling means.